Compass



Aug. 23, 1932.' g -A. URFI-:R 1,873,684

coMPAss f Fl d M 11 lzs w U 1 e ay f' vf I v i. Af/2f "g SUBSTITUTE FOR MISSING xFI 6W QN?! f Cw Mr-IN I 3f Il TZ' `l 1 I I l 32 5 ,I I /l M 33 I I I Flg.

z l 36 j C' i 41 I I I 'l IL 4f l I IIIIM 43 1 I trl l/ I l .1 u .A

l I I I I I IIIIII 34 IIl f 42 Y ADOLF URF ER rly disposed for facilitating reading of the compass-card. The type of compass illustrated in' F ig. 1 is -intended to ;be used as "an instrument mounted upon anrinstrument board ofthe i.v-i.^.- ,Hf 'f. in .':';".-l'."f.f z- Thisinvention relates to'compassesiand, Alubbers line 116 is'prope moreA particularly, tol means fon .providing g illumination of the compass-card and lubbers lnef liquid Compasses# fj. if; Le c a3 The primary object of this invention is to,

provide-means for` effectively illuminating characterltobe found on aircraft. The comi that portion of a compass-card Which must` pass iso-so positioned uponthe instrument beobserved. i board (not shown) as' to permit the lens' 11 to protrude from the rear of theinstrument board. It is a very important consideration and a' matter that directly affects the safeness desired to'be obtained While 'piloting {Another obj ectofthe inventionfis tol profvide illumination of Vthe lcompass-card of a liquid compass Without attendant obj ection-i able reflections and by maintaining the compassunit dark lexcept for thefeld of view alr'craft that instruments. used. -for .navi upontheeompasscard which is'desired-to beV gation purposes beV correctly villuminated Observed l v M E@ EL, y ym- .Pw m Withouty'at the ysame time, permitting the In accomplishing vthese objects light is' in. X1Ste110e of stray.' light which Y might troduced Without the compassfbowlthrough Serve to confuse a pilot and even make his 35e' surface of a lens or cover-glass for reflecting' A p :I Y i socket member 20,- Which in turn is carried o compass-card without reflection.

an optically cleanmember, suchas Aa'glass rod, which is so positioned as to cause rays of im light passing'therethrough to be cast upon t-he compass-card. Depending upon the type of compass with which the invention is tobe associated or upon the convenience permitted bya particular compass orcompass-mount.- t@ ino' the o ticall .clear membells so osi e P Y tioned as to c auseeither director indirect illumination of the compasscard Various Ways of utilizing the invention are illustrated in the drawing, in whichz; C

Figa 1 isa side view of a compass-bowl'With-v a. portion thereof broken away vso as to show the mannerof illuminating7 by reflection,- thei front of a compass-card. 5 Mizax; Figa 2 is a view illustratingv theluse of the 'I 3;"1 i. ^:!-.v f.' f HU: F ig.- 3 illustrates an installation by ivhich light may be caused to fall directly upon the The compass bowl 10, illustrated in Fig. l1 is of a type formed as a one-piece die-casting of Whichone side is left open for the purposev of mounting a'lens 11.. The compass-bowl is' 45v closedl atrits rear and sides by a'wall 12 and at-its top by another'wall 13Lallfof -which merge integrally and comprise a part ofthe die-castingThe, compass-bowlY '10 hasi a compasszcard chamber-114 containing liquidil 5U and'in compass-card-115y is mounted.

tion 'rearward' of'the yinstrument board".

`While the source of light 19 is illustrated as anelectric bulb Which is supported in ja by a mounting 21, itwill be appreciated that' some' other manner ofl causing illumination may be used. The mounting 21 is secured to a boss 22 by means of one or more screws 23 a similar opening 25 in' the Wall of thefcompass-bowl.' Opening'g has a bushing 26,' which `with thel assistance 'of a gasket 27, l serves toy support a glass-rod 28. This glassy Fig. 1.

In order to efficiently transmit light and preventloss thereof fronrthe'glass rodm28, at portions which are not 'intended to permit the escape of light, I cause the exterior of the glass rod 28 to be coated by an opaque coating such as silver. The coating used should prefferably have reflecting qualities. This coating extends'along the length of the rod but does not cover the ends when' prepared for use in the manner illustrated in Fig. 1. The construction of the -ro'd suggested is one which permits etlicient transmission of light from one end of the rod to the other end of the rod and its free passage therethrough.

Because of the position of the field of view desired to be observed upon the compass-card relative tothe side Wall or Walls of a compass-bowl, it is'desirable that some means be employed for the purpose of reflecting the light caused to enter Within theinterior of a compass-bowl'l from the exterior side of a Wall. Accordingly, as illustrated in Fig. 1 I have provided a shield 29 having polished reflecting surface thereon which is at such an angle fas to reflect the light received through the glass rod onto the field of view desired to be observed upon the compasscard. `This is an advantageous arrangement since it is very desirable that a small area of the compass-card be illuminated. Actually, it is only necessary to illuminate the lubbers line 1P and a small portion `of the compasscard 15 to the left and right of the lubbers line. It Will be appreciated that the reflecting surface 30 may be so formed as to direct the rays reflected therefrom in such a manner' as to illuminateonly the areas of the compass-card 'desired to be illuminated.

lIn Fig. 2 I have illustrated a glass rod 31 in the saine position and in the same relation as the glass rod 2S bears to the compass-bowl in However, in )lace of a specially constructed shield for the purpose of reflecting light upon the compass-card, I utilize in this instance, the outer surface 32 of the spherical lens 33 as a reflecting surface. The light leaving the glass rod 31 is directed against the convex surface of the lens Which is so shaped as to reflect this light upon the portion of the compass-card to be observed. In order that the reflecting conditions may be at their very best, it is preferable that surface 32 be silvered. 1

In Fig. 3, I have illustrated my invention in connection with a type of liquid compass which is intended to be used Where conditions are such as to permit the reading of the compass from any point about the exterior of the compass. This unit includes a glass Wall 3l in the form of a sleeve With its axis vertically disposed. A lower Wall (not shown) and an upper Wall 35 close the ends of the sleeve. In this type of a compass I mount the source of light 36 in a socket 37 carried by a. jacket 38. Jacket 38 has lugs 39 one on each side, by which it may be ,attached to thetop Wall by means of screws 40 or like fastening means? Jacket 38 has an opening 41 tlirouglrwhich `light may be permitted to pass. In this type of compass, the source of light may be placed exteriorly of one ofthe walls closing the ends of the vertically disposed glass sleeve34, and the compass-card 42 may be 'thereby illuminated Without reflection. @Accordingll a" glass rod 43 is placed Within an aperture in the Wall 35 and it is held therein by means of a nut 44 and gasket 45. In view of the fact that this rod need not be of an extensive length, the surface thereof need not' be silvered since it will be completely encased byy the material of the cover 35, the nut 4l' and gasket 45. However, the use of a silvered rodl is optional, but its use would permit the mostl efficient transmission of light to behad. `Itvv Will be appreciated that the light passing through the glass rod from the source of light Will be cast directly upon the field of view desired to be observed and that for this purpose the rod may be curved or of any length to suit the problem presented in vequipping various types of Compasses. f l' My invention 1s capable ofa Wide variation and relationship of parts Without departure fromv the nature and principle thereof and I' do not restrict myself unessentially` in the foregoing or other particulars,'lbut contem' plate such alterations and modifications"With-v in the scope of the appended claims as may be.

found to be advisable. 1l i 1. The combination with a compass bouil containing liquid and a 'compass-card therein,l of an optically clear member passing through a Wall of said compass-bowl, a source of light disposed in the vicinity of one end of said optically clear member, reflectingv means located so as to reflect light passing through said optically clear member upon the compass-card, and a'source of light disposed in the vicinity of one end of said optically clear.

bowl whereby the interior of said rod may be illuminated.

3. In combination, a compass-bowl having an opaque wall, a compass-card within said compass-bowl and surrounded with liquid, and optically clear means passing through said wall permitting the passage of light from the exterior of the wallto the interior of the compass-bowl, said optically clear means extending through the liquid and having a substantially opaque coating thereon preventing the escape of light within the com pass-bowl except as directed on said compasscard.

4. Iii combination, a compass-bowl comprising a Wall of opaque material and a lens, said coinpass-bowl containing liquid, a compass-card Viewablethrough said lens, a glass rod passing through said wall of opaque material and having a portion thereof immersed in the liquid, a socket member mounted on the outside of said Wall, and a lamp carried by said socket member and disposed opposite the end of said rod where it enters the compassbowl whereby light is directed from the outside of the wall through the glass rod and liquid, and to the compass-card.

5. In combination, a compass-bowl comprising a wall of opaque material and a lens mounted in a. vertical opening of said wall, said compass-bowl containing liquid, a coinpass-card having a vertical surface with indices thereon viewable through said lens, a glass rod mounted in the rear wall ofthe compass-bowl and extending through the liquid, said glass rod terminating in the vicinity of the area of the lubbers line at the front ofthe compass, a source of light iii the vicinity of the outside en d of said glass rod, and means for reflecting light transmitted from said source of light through said glass rod onto the lubbers line.

6. In combination, a compass-bowl comprising a wall of opaque material and a lens coutainingliquid. said lens being vertically disposed in a vertical opening of the wall. a compass-card viewable through said lens. a l(dass rod mounted in the wall opposite the lens and extending across the compass-bowl,

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a reflecting surface comprising surfaces of said lens whereby light transmitted through said glass rod is reflected to the compass-card, and a light mounted outside of said compassbowl opposite the end of said glass rod which is mounted in the wall.

7 In combination, a compass-bowl comprising a wall of opaque material and a4 lens containing liquid, said lens being vertically disposed in a vertical opening of the wall, a compass-card viewable through said lens, a glass rod mounted in the wall opposite thc lens and extending across the compass-bowl, a reflecting member to receive light transmitted through said glass rod and to reflect the same through said lens to the compass-caid,

SaidreHecting member fbeing mounted in ai' position outside of said compass-bowl and;

orward of said lens, and illumination means f in .the/vicinity of the end of said rodi-'which passes through .the Wall of the; compass-bowl.

8. In combination," na fcompassbowl comprsing-a glass wall in the form of a sleeve which is vertically disposed and closed'at-its ends, :sa-id compass-bowl .containing .liquid and a compass-card, vva glass ,rod'rmounted in the upper end wall ofsaid compass-bowl with? its axis in line with the portionof the "com-A pass-card desired to be observed, and a source of `light disposed exteriorly o'f said upper end" wall in thevicinity of the upper end of said glass'rod .whereby 'light .may befdirectedv through said glass rod and liquid and onto said compass-card; i-fxfza' -fff:fff ri'.

9. In combination, a compassowlcom-- prising'na 'glassv Wall in the form of a sleeve which is vertically disposed and closed at its ends, said compass-bowl containing liquid and acompass-card, a glass rod mounted in the upper end wall with its axis in line with the portion of the compass-card desired to be observed, a lamp mounting comprising a jacket fixed to the upper end wall, said jacket having an opening therein opposite the end of said glass rod at the outside of said wall, and a lamp mounted in said jacket opposite said opening whereby illumination from said lamp may be directed through said glass rod and onto said compass-card- 10. In combination with a compass bowl having a compass-card therein, of an optically clear member extending through a Wall of said compass-bowl, said member being coated with opaque material along its length to prevent the escape of light rays therefrom, a source of light disposed exteriorly of the compass-bowl and in the vicinity of one end of said optically clear member, and means disposed at the other end of said member Whereby light from said source may be introduced to the interior of said compass-bowl through said member.

11. The combination with a compass-bowl containing liquid and a compass card therein, of acover glass through which the card may be viewed, an optically clear member having an opaque surface and extending through a wall of said conipass-bowl into said liquid, and a source of light disposed in the vicinity of one end of said optically clear member so that light from said source may be introduced to the interior of the compass-bowl through said optically clear member without producing an external glare from the cover glass.

1Q. The combination with a compass-bowl containing liquid and a compass card therein of a cover glass through which the card may be viewed, a source of light disposed externally of said compass-bowl and enclosed so as to shut out light externally of the compassbowl', and means for directing the light from said source through the compass-bowl and through the liquid onto the compass card l Without producing an external glare from the cover glass and also for preventing refraction of light through the liquid. I r. i

i 13. The combination with a compsbwl il ternal glare from the cover glass and also for preventing refraction of light through the liquid. .if r r In testimony whereof I hereto afix my signature. l

ADOLF URFER.

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